The present invention relates to optical devices for locating by diascopy the position of a mobile element.
It is known that such a device comprises, a disk or strip comprising several tracks, each with a succession of fine alternating opaque (reflecting) and transparent zones and a reading assembly comprising, a light source and one or more photodetectors which detect for each track if it is an opaque zone (reflecting) or a transparent zone which is present in front of the photodetector(s). The disk or the strip and the reading assembly are mobile with respect to each other either in rotation (case of the disk) or in translation (case of the strip). In addition, an electronic unit may be associated with the photodetector(s) for processing the signals emitted by the photodetector(s).
Generally, the assembly of these components is disposed in a reduced volume, however, when these means are distant from each other, conductors provide the electric connections, between the power supply means, the optoelectronic system forming the reading assembly and the electronic signal processing unit.
In some applications, there exists a large distance between the reading assembly and the electronic signal processing unit. Any electric connection should be avoided between these two assemblies because such a connection would risk being disturbed by outside interferences, more particularly in the case of analog transmission of the signals between the reading assembly and the electronic signal processing unit.